Obesity is a growing epidemic. According to a National Center for Health Statistics report, as of 2006, more than 33% of the male and female adult population of the United States suffers from obesity. In 2003, the Department of Human Health Services reported that obese and overweight adults cost the United States over 69 billion dollars per year.
In response to this growing epidemic, the use of botulinum toxin injections have been reported in the treatment of obesity. See, WO 2002/13854. Current methods rely on injection of botulinum toxin directly in the muscle layer of the stomach. This injection technique requires the use of an endoscope to get the injection needle to the appropriate muscle layer of the stomach. Preliminary research also suggests that botulinum toxin injections can relax stomach muscles to facilitate ease of deployment of the gastric Lap Band®. See, e.g., WO 2007/106727. It is, however, a challenge for the physician to confirm that the injection needle is within the muscle layer of the stomach, which may account for the variability in the published clinical results of injection of botulinum toxin to treat obesity. See, for example, Topazian et al., Obes. Surg., 2008, 18:401-407. Furthermore, the gastric wall is thinner in the fundus and body as compared to the antrum. A treatment method that is capable of delivering the botulinum toxin without the potential complications associated with surgical procedures or the need for local, regional, or general anesthesia is desirable.